Mighty Goat

No cat or egr on on the 03-04 manual HO trucks. that is a 305/555 truck. And the lift pump is a truly easy fix. Just read up a bit and but a GDP kit inline an forget about it. Fortunately my truck already had the OEM in tank kit but I was in Iraq and didn't know that so I researched it on here and built one out of parts before I got home and actually built the fuel system when I got home. But, don't let that little thing scare you away from a 305/555 HO. My next move is 3.73 gears so I can get 22+mpg. Right now w/4.10's I only get 22mpg if I'm below 65 and that's on 285/70's. So, If you want the best of both worlds, power and MPG, get a 305/555 with 3.73's.

cad14man

I just hit 80K miles this evening. my LP died @ 52K miles. I get 19.5 mpg in the city and 23 mpg on the hwy. my truck is 100% stock

Ohioplower

What I was asking about the cat and egr valves was about the 04.5 and up trucks. Sorry I should have specified.

Toto

I have an 04 305 555 runs great, good mileage(2wd).
I have had the high idle activatied.
The only problem I have had is the lift pump failed.
Replaced under warranty with in tank version from DC.
Some other small stuff but nothing worth mentioning.

donhov

The newer only have the cats, still no EGR that I am aware of. The 04's seem to get somewhat better millage then the 04.5'ws but my 07 went from Florida to mich with no trailer and running 80MPH and got an average of 21 MPG each way. It is the 5.9 engine, mostly stock. My 04.5 on 1 occasion got 22 mpg, not a mistake, but it was an exception. When it was running well usually got 17-18 and with 5th wheel was well to get 9-10. The new truck gets 16-20 empty and 12 or so towing.

I have to believe that it depends on the truck and wheather you got a good one or not....there are a few lemons out there.

surfram

76k and zero problems. Still running on the stock lift pump.

Ohioplower

I thought you couldnt get high idle on the 305/555's, am I wrong? Do the 04.5 and up trucks have egr valves? I thought they did but am I wrong?

johnr9q

So if I got a 03 to 04.5 with the standard output should I expect to get worse MPG than with the 305/555 HO? What is the HP/Torque on the SO? Were there more of the HO's sold? Like I said earlier, I totaled my 99 2 days ago and really need to get a newer truck soon but don't want to get one that gets 14 mpg at 65 like I read about here in the forums. I got 22 MPG with my 99 at 65.

JCLeary

My '03 305/555 was a much better truck than my '07. 4 miles per gallon better fuel economy (city and highway) even when lifted w/ 35" tires. The truck was also "screwed together" better. No rattles and squeaks at all, where my '07 has both. The '03 ran better, idled better, and generally "felt" better than my '07.

I'm kicking myself for selling it.

The easiest way to check which motor it has is by the valve cover. If not, then by the build date. If it was built in '03, then it's a 305/555. If it was built 1-04 or later it's a 325/600.

I will say that the 04.5 and 05 trucks are great too. DC cheapened the trucks up for '06 and '07. It shows.

surfram

I had the high idle enabled by the dealer for free. I run 16-18mpg around town and 19-21mpg on the highway (70mph or under).

Ohioplower

Well I drove a 03 and 05 today and I like the 05 better. Theres alot more power.

rip 112

Nothing wrong with the 05s, besides the plastic intercooler sides. I'm at 78000 with no mechanical problems whatsoever.

triplenickel

You see allot less injector problems on the 03-04 rigs as well.

Mighty Goat

Yep. 03-04 need injectors. 05's need intercoolers and overdrive units in manuals. But, the bottom line is that for a stock truck, the 03-04 with 3.73 or 4.10 gear will produce more mpg and isn't emissions restricted. And I'm not saying this b/c I have an 03 b/c I actually want the latest 07 5.9, G56 you can buy. But, it's still the truth.

C Schomer

I held out til I found a very cherry 03 (built 10-02) with 25k miles. I drove two 325s and several 305s before I got my 03. The 325s weren't nearly enough better to make me go for the lower mpg. My liftpump was weak and the Walbro on the side of the frame, very easy to service, sounded a bunch better than the intank pump. I haven't had any of the early 03 problems, like injectors, vibrations, broken alternator bracket, wind leaks or u-joints and the A/C is terrific! I'm still glad I went this way and wouldn't trade it for any 325. Craig